Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond them: prices are TTC and in euros, and the result is a per-vehicle price rather than a single quote, which partially compensates for the absent output schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with what the tool returns then when to call it then a pricing caveat. Every sentence carries distinct information with no repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only pricing tool with no output schema, the description conveys the return shape (price per vehicle), the units (TTC euros), and the workflow position. Remaining gaps such as error behavior for unserviceable addresses or whether quotes expire are minor.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 78% with rich per-parameter descriptions (address format, enum meaning, heure de Paris ISO 8601, maxItems). The description only echoes date and trip-type concepts at a high level and adds no syntax or constraint detail beyond the schema, so the baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Donne le prix fixe de chaque vehicule') plus the scope (trajet ou mise a disposition, a une date donnee), which is exactly the distinction between the two modes it supports. It also implicitly separates itself from the booking sibling by instructing to call it before any reservation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'A appeler avant toute reservation' gives clear temporal context for when this tool belongs in the workflow. It does not name a specific alternative or state when-not to use it, so it stops short of full routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.